Electromagnetically operated vacuum sealed relay



Oct. 18, 1949. KfR. VALE ErAL f ELECTROMAGNETICALLY OPERATED VACUUMl SEALEDLRELAY 2 Sheets-Sheet 1 Filed Oct. 19, 1945 INVENTORS izlz R. Vale /l 33 la/z L. 376275022 s By ATTORNEY Oct. 18, 1949. K. R. VALE ETAL 2,435,024

ELECTROMAGNETICALLY OPERATED VACUUM SEALED-RELAY Filed Oct. 19, 1945 2 Sheets-Sheet 2 ATTORNEY INVENTORS u {ffii/z f?. Vale Jaim 558/175072 Z7 Zi@ i; /5 ffy ww/V Patented Oct. 18, 1949 ELECTROMAGNETICAILY OPERATED VACUUM SEALED RELAY Keith Robert Vale and John Ernest Benson, Sydney, New South Wales, Australia, assignors to Amalgamated Wireless (Australasia) Limited, Sydney, New South Wales, Australia, a company of New South Wales 'Application october 19, 1945,serisl No. 623,364 v In Australia March 21, 1945 This invention relates to electromagneticallyoperated vacuum-sealed relays primarily adapted for use in making and breaking high voltage contacts, and has particularV application in aircraft apparatus operating at low atmospheric pressures.

In the past, various types of vacuum-sealed relays have been suggested for this purpose but all have suffered from one or more disadvantages which limited the scope of usefulness.

A primary disadvantage appears to reside in low eiiiciency which is due, chieily, to circumstances arising out of the fact that it is impossible adequately to evacuate the relay when the magnetizing coil is located within the sealed con,- tainer.k

Consequently, it is necessary to locate the magnetiz'ing coil outside the evacuated container which houses the switching contacts and, in conventional relays of the type referred to, the arrangement of the magnetizing coil has been such that the length of the magnetic path is considerably longer than that which could be realized if it were possible to locate the magnetizing coil within the evacuated container.

This results in loss of eiciency because a magnetizing coil of considerably increased proportions and higher operating potentials is requiredvto produce an equivalent magnetizing iiux. It will also be obvious that any increase in the physical dimensions of the magnetizing coil produces a consequential increase in weight; an undesirable characteristic particularly where the relay is desired for use in aircraft applications.

The object of the present invention is materially to reduce the size and weight of the magnetizing coil and at the same time greatly to improve the efficiency of an evacuate relay employing a magnetizing coil outside the evacuated container.

The above objective is achieved in accordance with the present invention by locating the core or pole piece of the magnet and the armature of the relay, together with that portion of an evacuated container within which said core and armature are supported, within the core space of an associate magnetizing coil in such a manner that the axis of the armature lies parallel to or coincident with the axis of the core, and by providing means at either or both ends of the core for reducing the length of the magnetic path.

However, for a more complete understanding of the subject invention, practical embodiments thereof will now be described with reference to the accompanying drawings wherein- Figure 1 is a vertical sectional view of a vacuum 3 Claims. (Cl. 20G-87) sealed relay ln accordance with this invention` and adapted for high voltage operation.

Figure 2 is a fragmentary sectional elevation at right angles to Figure 1;

Figure 3 is a perspective view of a yoke member; and

Figure 4 is a fragmentary sectional view,equlvalent to Figure l, but illustrating a modiiied envelope construction for use when one electrode of the relayis to operate at low voltage.

Referring now in particular to Figures 1, 2, y and 3 of above mentioned drawings, I0 indicates a glass envelope which is evacuated and sealed. off, said envelope being formed with a pairof angulariy related electrode supporting arms I2' each incorporating a bubble I3 for increasing the leakage path.

Tungsten electrodes or contacts are indicated by references I4, I5 and I6.

The electrode i4 carries a magnetic core or pole assembly comprising a soft iron base member Il onto whichis threaded a pole-piece i8 of similar materiaLe. g. Armco iron, and between `member I1 and pole-piece I8 are mounted a soit iron washer I9 and a micalex washer 20, they relative dimensionsrof said washers being such that insulating washer 2D maintains the only slightly smaller iron washer I9 just out of contact with the interior wall surface of envelope I0. A soft iron armature 2 i formed with oppositely disposed lugs 22, is mounted on the free ends oi a pair of tungsten spring legs 23 projecting from washer I9, opposite faces of said armature, near the outer end, being provided with tungsten contacts I5a, iGa. Pole-piece I8 is providedwith a radially kdisposed through aperture 24 to enable evacuation of the screw threaded interior thereof, and near of residual magnetism.

the reduced upper end of said pole-piece there is provided a limiting stop 25, of non-magnetic metal, to prevent armature 2l from touching and sticking to the pole-piece under the influence g The upper end of polel-piece I8 is reduced as shown in Figure 1 to enable armature 2| to lie substantially in the axial plane of said pole-piece.

As illustrated by Figure 1, the neck portion of envelope I0 ywith the above described assembly located therein is mounted withinthe centralk bore of a non-magnetic bobbin`26 carrying relay winding 21, the envelope i0 being secured in position within'bobbin 26 by means of a wax 28 so that portions of a soft-iron yoke 29, now to be described, are aligned with lugs 22 and washer I9.

The yoke 29, illustrated in detail in Figure 3,

3 comprises a reclining U-shaped member having awebllsndupperandloweriianges Il and 22 respectively, the upper flange 3l being provided with an opposed pair oi ears 23 while the lower :lange 32 is formed with a through aperture! In the illustrated example. the yoke 2l is securedtothebobbinbymeansoiboltsil passedthroughilangestl andl2.

Theear'sll areiormed by twisting the parallelly disposed lugs 8l. projecting from flange 8l,

.whereby the so formed ears are adapted to lie` closely adJacent the envelope Il in transverse alignment with the lugs 22 on armature 2i.

Similarly,'the aperture Il in flange I2 o! yoke 2l is transversely aligned with washer Il associated with pole-piece Il.

It desired, an insulated terminal board or strip may be mounted on web Il of yoke 20.

The eective magnetic path in the above-described arrangement may be traced from ilange 32, through the wall of aperture 34 to washer Il and pole-piece Il. across gap to armature 2|, from lugs 22 on the latter to ears I3 on ilange 32 and nally through the latter and web Il back to flange 3i.

It will therefore be appreciated that the path deilned is constituted entirely of iron except for the relatively small gaps 34-l6, l92| and 22-33.

In the inoperative or non-energized condition, contacts l5, lia are made but in the operative or energised condition of the relay, the free end of the pole-piece i3 becomes polarized in opposite sense to the adjacent end of armature 2i and the magnetic force pulls said armature across to make contacts 16a, I6.

Since lugs 22 and ears 33 are disposed in planes that are parallel to the path of motion of armature 2i, the forces acting on lugs 22 are at right angles to such path and cannot retard free action of armature 2| in either direction along said path. Moreover, the reluctance of the gap (22-33) may be considerably reduced by making the lugs 22 as large as practicable.

From Figures 1 and 2 it will be observed that armature 2l extends beyond the free end oi polepiece il; this disposition is necessary when it is desired that said armature be attracted to. and not repelled by, pole-piece i8.

Therefore, although the illustrative example described above, requires armature 2i to be attracted to the core or pole-piece I8 it will be evident that the physical dimensions of the pole and armature may be related as above vindicated to attain a repelling action without departing from the instant invention.

Figure 4 illustrates a modication of the enyvelope i for use when one electrode (e. g. 15) is to operate at a low potential and, in view of the foregoing, no further description of the last mentioned figure is deemed necessary.

Finally, it is to be noted that the subject relays will still operate with a reasonable degree of emciency in the absence oi' ears 33 and lugs 22 but then the iiux path outside of the iron would be longer with consequential higher reluctance.

What is claimed is:

1. An electromagnetically operated vacuumsealed relay comprising an evacuated envelope housing a plurality of switching contacts, one of said switching contacts carrying a relay polement with, and in closely spaced relation to, a

pair oi transversely aligned lugs provided one on each longitudinal edge of said amature, the other end oi' said yoke member being in transverse augment with, and closely spaced from, said magnetic washer.

2. A relay according to claim l and wherein said armature is mounted on said magnetic wash- 'er by means of a pair of spring legs extending from said washer.

3. An electromagnetically operated, vacuumsealed relay comprising an evacuated envelope housing a plurality of switching contacts, one oi said switching contacts carrying a relay pole piece whereof the upper end is reduced to permit location of an armature substantially in the axial plane of said pole piece, said armature being mounted on a magnetic washer member in contact with the other end of said pole piece. the others of said contacts being mounted for cooperation with said amature, the portion oi said envelope containing said pole piece and armature being mounted within the core space -of an associated magnetizing coil. and a magnetic yoke member of U-formation embracing said coil and having one of its ends located in transverse alignment with, and in closely spaced relation to a pair of transversely aligned lugs provided one on each longitudinal edge oi said amature, the other end of said yoke member being in transverse alignment with and closely spaced from said magnetic washer, said magnetic washer being annularly spaced from the interior surface of said envelope by means of said insulating washer which is slightly larger in diameter than said magnetic washer, said insulating washer being mounted between said magnetic washer and a base member carried by said one electrode.

KEITH ROBERT VALE. JOHN ERNEST BENSON.

REFERENCES CITED The following references are oi record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 684,378 Potter Oct. 8, 1901 1,558,277 Phelan et al Oct. 20, 1925 1,638,725 Proctor Dec. 15, 1931 2,001,579 Leece et al May 14, 1935 2,029,267 Lecce et al Jan. 28, 1936 2,037,535 Rankin Apr. 14, 1936 2,053,102 Palmer Sept. l, 1936 2,060,235 Miller Nov. 10, 1936 2,064,477 Larson Dec. 15, 1936 2,242,636 Wilson May 20, 1941 2,277,215 Ellwood Mar. 24, 1942 2,360,941 Eitel et a1 Oct. 24, 1944 

